Reenforced sand core and method of making same



Feb. 12 1924., 1,483372 W. H. MILLSPAUGH REEI'NFORCED SAND CORE AND METHOD OF MAKING SAME Filed Jan. 10, 19-20 2 Sheets-Sheet. 1

Feb, 12 1924.

W. H. MILLSPAUGH REENFORCED SAND CORE AND METHOD OF MAKING SAME Filed Jan. 10 1920 2 Sheets-Sheet 2 Patents Feb. 12, I924.

UlTED STATES WILLIAM H. MILLSPAUGH, OF SANDUSKY, OHIO.

REENFORCED SAND CORE AND METHOD OF MAKING SAME.

Application filed January 10, 1920. Serial No. 350,548.

To all whom it may cancer-n:

Be it known that 1, WILLIAM H. MILLS- PAUGH', a citizen of the United States of America, and a resident of 'Sandusky, county of Erie, and State of Ohio, have invented.

certain new and useful Improvements in Reenforced Sand Cores and Methods of Making Same, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

This invention relates to reenforced sand cores and method of making same, and its object is to provide a sand core which although collapsible is strong and capable of withstanding great strains, and to provide a simple method of making such cores. Another object is to provide a metallic support for such cores which is so arranged that the core may be handled safely and which will take some of the strains put upon the core in use. Another object is to form a reinforcement for sand cores whichshall keep them intact when subjected to strains in one direction and to so construct the core that it will collapse when subjected to strains in the opposite direction. More specifically, its object is to provide sand cores of the aforesaid charactertistics which are especially adapted for use in centrifugal casting machines, and still more specifically, constructed and arranged to form in such machines the belLends of cast iron or other metallic pipe.

These and other objects of the invention will appear in the following specification in which I will describe the invention, the

i novel features of which will be set forth in appended claims.

Referring to the drawings:

Figure 1 is a sectional elevation of a centrifugal mold with a core support therein, which. is made according to and embodies this invention.

Figure 2 is an end elevation of the parts .shown in Figure 1.

Figure 3 is a sectional elevation of a part of a molding table together with one of my novel core supports, a sand core mold and a Figure 5 is a sectional elevation of a part of a centrifugal molding machine with one of thesenovel sand cores therein together with the bell end of a cast metal pipe.

Figure 6 is a perspective view of the bell end of a pipe formed in such a machine with one of these cores.

7 Like characters of reference designate corresponding parts in all the figures of the drawings.

In Fig. 1, 10 designates a rotary mold and 11 a shaft by means of which it is supported and rotated. 12 is a face plate provided with a central opening 13 which is adapted to be affixed to the end of the mold 10 by bolts 14. This face plate also may be 'constructed with projecting lugs 15.

This mold is also provided with longitudinal kets spaced between the lugs 15. Hea ed pins 16 are inserted in these pockets and held in place by the face plate. The mold 10 may be provided with a recess which is tapered or beveled as shown at 18. I i

The first step in the method of construct ing cores in accordance with this invention, is to arrange the arts of the rotary mold which have been escribed specifically and to pour into it through the opening 13 molten metal while the mold is rotating.

This will form a short cylindrical casting 20 with an outstanding flange 21 at one of its ends in which the pins 16 will be firmly embedded. When the face plate 12 is removed the lugs 15 will be withdrawn leaving in the casting at the junction of the body thereof and its flange a pluralit of openings 22 between the ins 16. The. lugs 15 are preferably tapere to facilitate their removal, or if desired, these openin may be cut through the flange instead of fling cast therein.

The casting thus formed will hereinafter be called the support, which will then be placed upon a molding table such as 30 in Figure 3. This molding table is provided with a, verticall movable frame 31 under it with lugs 32 w ich. project up through the table. These are pushed upwardly by suitable mechanism comprising a rod 33 which is provided for the purpose of also pulling the lugs 32 downwardly below the upper surface of the table 30.

The lugs 32 pass through the holes 22 in the core support and extend along the outer periphery of the cylindrical portion thereof.

Rings 35 are next placed around the pins 16. These rings may be of plain or crimped wire or may be wound into the form of spirals of spring wire, so that theirresilienwill cause them to. be held tightly around t e pins 16.

Next a split mold 36-87 which is adapted to fit around the flange of the core support,

' is placed upon the table and the space hetween it and the core support is filled with core sand to form the collar or body 38. The lugs 32 may be withdrawn and the core box 3637 removed after the core body has been formed in this manner. After this the core may be baked on its support or treated in any desired manner to harden it.

The manner in which this core is used may be seen from Fig. 5. In this figure 40 designates the rotary mold of a centrifugal casting machine. The core which is made in the manner described fits into the end of this mold in the manner shown in Fig. 5, and may be held in place thereon in any desired manner. Molten metal may be poured into mold 40 while it is rotating from either end thereof by suitable means such as that shown and described in my former Patent No. 1,058,250, dated April 8, 1913, and this will result in the formation of a pipe, the bell end of which is shown in Figures 5 and 6, and designated by the reference numeral 50.

Centrifugal casting machines are arranged to be rotated at high rates of speed, consequently when sand cores are used as in the case herein illustrated, they are subjected to great strains on account of centrifugal force. The core which I have invented may be handled easily without danger of breakage by being grasped by the parts thereof which are made of metal. The flange of the core support is the part thereof which engages the mold 40 of the centrifugal casting ma-' chine, so that it may be clamped in place securely without breaking the sand, and during the rotation of the mold 40 the reinforcement of the core prevents it flying apart. The beveled part at 18 also prevents breakage of the core under centrifugal force.

When a casting such as that illustrated in Figs. 5 and 6 is made in a centrifugal casting machine, it contracts to a considerable amount when it is cooled. In order to insure a perfect casting it is desirable to have the core. collapse during this period of shrinkage, and it is for the purpose of insuring the collapse of the sand core without undue strains coming upon the cast metal, that I have provided the crush cavities 32 in the inner periphery of the sand core formed therein by the lugs 32, in the manner shown in Fig. 3. These crush cavities do not weaken the core while it is being handled or while it is being used during the pouring of the metal, but they do effectively weaken the core against suchinward pressure as is brought upon it by the aforesaid shrinkage.

lVhile I have described this core as made for and used in centrifugal casting machines, I realize that it is applicable to other forms of apparatus, and I do not intend to limit the invention to any specific use. It is also possible to vary the form and construction of the core without departing from the spirit and scope of this invention, and I intend no limitations other than those imposed by the appended claims.

lVhat I claim is: v

1. A core for use in centrifugal casting machines comprising a metallic support in. the form of a tube having an integral outwardly extending radial flange at one end, pins projecting from the flange in spaced concentric relation with respect to the tube and a collar of sand surrounding the tube and embedding said pins, said pins strengthening the core and preventing destruction thereof by centrifugal force.

2. A core comprising a metallic support in the form of a tube having an outwardly extending radial flange at one end, pins projecting from the flange in spaced concentric relation with the tube, a flexible reinforcing strip around and supported by the pins, and a collar ofsand surrounding the tube and embedding said pins and strip.

3. A core for use in centrifugal casting machine comprising a metallic hollow shell having an integral flange projecting laterally from one end thereof, pins projecting from the flange and spaced from the shell and a collar of sand around said flange and surrounding the shell and embedding said pins, said pins strengthening the core and preventing destruction thereof by centrifugal force.

4:. A core comprising a metallic hollow shell having a flange projecting from one end thereof, pins projecting from the flange and spaced from said shell, a flexible reinforcing strip around and supported b the pins, and a collar of sand upon the ange surounding the shell and embedding said pins and strip, the flange being wider than the collar.

5. A core for use in centrifugal casting machines comprising a metallic hollow cylindrical shell having an integrahflange projecting from one end thereof, pins parallel with the cylindrical shell spaced from said shell and projecting from the flange, and a collar of sand upon the flange surrounding the shell and embedding said pins, the flange being wider than the collar, said pins strengthening the core and preventing destruction thereof by centrifugal force.

6. A core comprising a metallic hollow cylindrical shell and a flange projecting from one end thereof said flange having an under-cut beveled portion near the shell,

and a collar of sand upon the flange surrounding the shell, the collar extending beyond the undercut portion but terminating short of the flange.

7. A core comprising a metallic hollow shell with a flange projecting therefrom and a collar of sand upon the flange surrounding the shell, said collar being interiorly grooved to form spaced crush cavities adjacent to said shell.

8. A core comprising a metallic hollow shell and a flange projecting therefrom with pins spaced from said shell, projecting from the flange, and a collar of sand upon the flange surrounding the shell and embedding said pins, said collar being interiorly grooved to form crush cavities adjacent the shell between the pins.

9. A core comprising a metallic hollow cylindrical shell and a flange projecting from one end thereof with pins parallel with the cylindrical shell spaced from said shell,

projecting from the flange, a flexible reinforcing strip around and supported by the pins, and a collar of sand upon the flange surrounding the shell and embedding said pins and strip, said collar being interiorly grooved to form crush cavities adjacent the shell between the pins.

10. A core comprising a metallic hollow cylindrical shell and a flange projecting from one end thereof with pins parallel with the cylindrical shell spaced from said shell, projecting from the flange, a flexible reinforcing strip around and supported by the pins, said flange having an under-cut beveled portion near the shell, and a collar of sand upon the flange surrounding the shell and embedding said pins and strip, said collar being exteriorly grooved to form crush cavities adjacent the shell between the pins.

In witness whereof, I have hereunto set my hand this 5th day of January, 1920.

WILLIAM H. MILLSPAUGH. 

